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Subject: Re: How many programs can see the draw in the 2nd game of DB vs Kasparov?

Author: Enrique Irazoqui

Date: 15:23:36 03/01/01

Go up one level in this thread


On February 28, 2001 at 14:13:56, Uri Blass wrote:

>On February 28, 2001 at 13:41:31, Robert Hyatt wrote:
>
>>On February 28, 2001 at 12:19:42, Uri Blass wrote:
>>
>>>On February 28, 2001 at 11:46:37, Enrique Irazoqui wrote:
>>>
>>>>On February 28, 2001 at 10:54:13, Uri Blass wrote:
>>>>
>>>>>On February 28, 2001 at 09:57:06, Enrique Irazoqui wrote:
>>>>>
>>>>>>On February 28, 2001 at 07:21:44, Jeremiah Penery wrote:
>>>>>>
>>>>>>>On February 27, 2001 at 13:35:33, Enrique Irazoqui wrote:
>>>>>>>
>>>>>>>>On February 27, 2001 at 10:49:29, Uri Blass wrote:
>>>>>>>>
>>>>>>>>>On February 27, 2001 at 10:07:31, Robert Hyatt wrote:
>>>>>>>>>
>>>>>>>>>>On February 27, 2001 at 08:24:14, Jorge Pichard wrote:
>>>>>>>>>>
>>>>>>>>>>>I believe that the drawish move was Qe3! instead of the Qxc6?  Can somebody
>>>>>>>>>>>post the FEN string that produce the graphical position for me. Plus I wonder
>>>>>>>>>>>what program save the draw in the shortest time possible?
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>>None can see this.  It is a 60+ ply repetition.  Way beyond anything we can
>>>>>>>>>>see today.
>>>>>>>>>
>>>>>>>>>We need to test all the programs in order to say that none can see it.
>>>>>>>>>
>>>>>>>>>Some programs like dark thought are not available so we cannot know that none
>>>>>>>>>can see it.
>>>>>>>>>
>>>>>>>>>The fact that it is 60 ply repetition is not a proof that none can see it
>>>>>>>>>because programs only to need the right extensions to see the relevant 60 plies
>>>>>>>>>forward.
>>>>>>>>>
>>>>>>>>>If you are wrong then testing only one program is enough to prove it.
>>>>>>>>>
>>>>>>>>>Uri
>>>>>>>>
>>>>>>>>Deep Fritz doesn't see the draw yet after one hour, but it's getting there. Now
>>>>>>>>I am trying with Deep Shredder and I might leave one of them computing the
>>>>>>>>position overnight.
>>>>>>>>
>>>>>>>>What has been the evaluation that came closest to 0.00?
>>>>>>>>
>>>>>>>>Enrique
>>>>>>>>
>>>>>>>>Comp Deep Blue - Kasparov,G
>>>>>>>>1r6/5kp1/RqQb1p1p/1p1PpP2/1Pp1B3/2P4P/6P1/5K2 b - - 0 1
>>>>>>>>
>>>>>>>>Analysis by DEEP FRITZ   :
>>>>>>>>
>>>>>>><SNIP>
>>>>>>>>45...Qe3 46.Qxd6 Re8 47.h4 h5 48.Bf3 Qc1+ 49.Kf2 Qd2+ 50.Be2 Qf4+ 51.Kg1
>>>>>>>>  ±  (1.00)   Depth: 19/50   00:25:38  1907813kN
>>>>>>>>45...Qe3!
>>>>>>>>  ²  (0.69)   Depth: 20/52   00:56:36  4195172kN
>>>>>>>>
>>>>>>>>(Irazoqui, Cadaqués 27.02.2001)
>>>>>>>
>>>>>>>I have let various versions of Crafty search this position for very long periods
>>>>>>>of time in the past.  I've had it return what looks like a draw score at around
>>>>>>>ply 21 or so, and then at the next ply the score will go back up and the line
>>>>>>>will change a lot!  I never could figure out why this was.
>>>>>>>
>>>>>>>BTW, there is a good line posted at the bottom of http://www.rebel.nl/db2.htm
>>>>>>>for this position.  It looks like Fritz is following it fairly well so far, but
>>>>>>>Crafty also looked to be following it when it found the drawscore, then it
>>>>>>>changed its mind away from the line, and again the score started to rise. :(
>>>>>>
>>>>>>Same thing with Deep Fritz. What I find surprising is that Deep Blue expected
>>>>>>46... Qxc6, when Deep Fritz, Deep Shredder beta and Junior 7 beta, for instance,
>>>>>>pick Qe3 very quickly.
>>>>>>
>>>>>>Enrique
>>>>>>
>>>>>>
>>>>>>Comp Deep Blue - Kasparov,G
>>>>>>1r6/5kp1/RqQb1p1p/1p1PpP2/1Pp1B3/2P4P/6P1/5K2 b - - 0 1
>>>>>>
>>>>>>Analysis by DEEP FRITZ   :
>>>>>>
>>>>>>45...Qxc6
>>>>>>  ±  (0.91)   Depth: 1/6   00:00:00
>>>>>>45...Qxc6 46.dxc6 Be7 47.Bd5+ Ke8 48.c7 Rc8 49.Ra7
>>>>>>  ±  (1.16)   Depth: 6/15   00:00:00  10kN
>>>>>>45...Qxc6 46.dxc6 Be7 47.Bd5+ Ke8 48.c7 Rc8 49.Ra7
>>>>>>  ±  (1.16)   Depth: 6/15   00:00:00  10kN
>>>>>>45...Qxc6 46.dxc6 Be7 47.Bd5+ Ke8 48.c7 Rc8 49.Ra7
>>>>>>  ±  (1.16)   Depth: 6/15   00:00:00  10kN
>>>>>>45...Qxc6 46.dxc6 Be7 47.Bd5+ Ke8 48.c7 Rc8 49.Ra7
>>>>>>  ±  (1.16)   Depth: 6/15   00:00:00  10kN
>>>>>>45...Qxc6 46.dxc6 Be7 47.Bd5+ Ke8 48.c7 Rc8 49.Ra7
>>>>>>  ±  (1.16)   Depth: 6/15   00:00:00  10kN
>>>>>>45...Qxc6 46.dxc6 Be7 47.Bd5+ Ke8 48.c7 Rc8 49.Ra7
>>>>>>  ±  (1.16)   Depth: 6/15   00:00:00  10kN
>>>>>>45...Qxc6 46.dxc6 Bc7 47.Ra7 Rc8 48.Rb7 Ke7 49.Rxb5
>>>>>>  ±  (1.37)   Depth: 7/16   00:00:00  31kN
>>>>>>45...Qxc6 46.dxc6 Bc7 47.Ra7 Rc8 48.Rb7 Ke7 49.Ke2 Kd6 50.Rxb5
>>>>>>  +-  (1.44)   Depth: 8/17   00:00:00  65kN
>>>>>>45...Qxc6 46.dxc6 Bc7 47.Ra7 Rc8 48.Rb7 Ke7 49.Ke2 Kd6 50.Rxb5
>>>>>>  +-  (1.44)   Depth: 9/19   00:00:00  115kN
>>>>>>45...Qxc6 46.dxc6 Kf8 47.Ra7 Rc8 48.Rb7 Ra8 49.Rxb5 Ra3 50.Rd5 Ke7
>>>>>>  +-  (1.53)   Depth: 10/22   00:00:00  305kN
>>>>>>45...Qxc6 46.dxc6 Kf8 47.Ra7 Rc8 48.Rb7 Rc7 49.Rxb5 Ke7
>>>>>>  +-  (1.56)   Depth: 11/21   00:00:00  1078kN
>>>>>>45...Qxc6 46.dxc6 Kf8 47.Ra7 Rc8 48.Rb7 Rc7 49.Rxb5 Ke7
>>>>>>  +-  (1.56)   Depth: 12/22   00:00:01  1597kN
>>>>>>45...Qxc6 46.dxc6 Rc8 47.Ra5 Ke7 48.Rxb5 h5 49.Bd5 Rb8 50.Rxb8 Bxb8
>>>>>>  +-  (1.78)   Depth: 13/26   00:00:02  3199kN
>>>>>>45...Qxc6 46.dxc6 Rc8 47.Ra5 h5 48.Rxb5 h4 49.Rb7+ Rc7 50.Bd5+ Ke7 51.Bxc4
>>>>>>  +-  (1.84)   Depth: 14/26   00:00:06  6898kN
>>>>>>45...Qe3!
>>>>>>  +-  (1.81)   Depth: 14/39   00:00:21  25200kN
>>>>>>45...Qe3! 46.Qd7+ Kg8 47.Qxd6 Rf8 48.Qe6+ Kh7 49.Qe7 Rg8 50.Bf3 Qc1+ 51.Kf2
>>>>>>  ±  (1.22)   Depth: 14/39   00:00:29  34959kN
>>>>>>45...Qe3 46.Qxd6 Re8 47.h4 Re7 48.Bf3 Qc1+ 49.Kf2 Qd2+ 50.Kg3 Qe1+ 51.Kh3
>>>>>>  ±  (1.16)   Depth: 15/39   00:00:58  71272kN
>>>>>>45...Qe3 46.Qxd6 Re8 47.h4 h5 48.Bf3 Qc1+ 49.Kf2 Qd2+ 50.Be2 Qf4+ 51.Kg1
>>>>>>  ±  (1.28)   Depth: 16/43   00:01:48  133552kN
>>>>>>45...Qe3 46.Qxd6 Re8 47.h4 h5 48.Bf3 Qc1+ 49.Kf2 Qd2+ 50.Be2 Qf4+ 51.Bf3
>>>>>>  ±  (1.28)   Depth: 17/45   00:04:03  301257kN
>>>>>>45...Qe3 46.Qxd6 Re8 47.h4 h5 48.Bf3 Qc1+ 49.Kf2 Qd2+ 50.Be2 Qf4+ 51.Bf3
>>>>>>  ±  (1.28)   Depth: 18/46   00:09:44  723368kN
>>>>>>45...Qe3 46.Qxd6 Re8 47.h4 h5 48.Bf3 Qc1+ 49.Kf2 Qd2+ 50.Be2 Qf4+ 51.Kg1
>>>>>>  ±  (1.06)   Depth: 19/50   00:22:41  1678502kN
>>>>>>45...Qe3 46.Qxd6 Re8 47.h4 h5 48.Bf3 Qc1+ 49.Kf2 Qd2+ 50.Be2 Qf4+ 51.Kg1
>>>>>>  ±  (1.00)   Depth: 20/49   01:04:45  4818191kN
>>>>>>45...Qe3!
>>>>>>  ²  (0.69)   Depth: 21/54   02:32:36  11295715kN
>>>>>>45...Qe3! 46.Qxd6 Re8 47.h4 h5 48.Bf3 Qc1+ 49.Kf2 Qd2+ 50.Be2 Qf4+ 51.Kg1
>>>>>>  ²  (0.31)   Depth: 21/54   04:29:02  19961605kN
>>>>>>45...Qe3 46.Qxd6 Re8 47.Qd7+ Re7 48.Qc6 Qxe4 49.d6 Qxf5+ 50.Kg1 Rd7 51.Qxb5
>>>>>>  ²  (0.31)   Depth: 22/57   09:15:31  41587594kN
>>>>>>45...Qe3 46.Qxd6 Re8 47.Qd7+ Re7 48.Qc6 Qxe4 49.d6 Qxf5+ 50.Kg1 Rd7 51.Qxb5
>>>>>>  ²  (0.47)   Depth: 23/56   17:29:25  78776519kN, tb=3
>>>>>>
>>>>>>(Irazoqui, Cadaqués 28.02.2001)
>>>>>
>>>>>Compare to the analysis of yace after few hours of playing against itself and
>>>>>going back.
>>>>>
>>>>>1...Qe3 2.Qxd6 Re8 3.Qd7+ Re7 4.Qc6 Qxe4 5.d6 Qd3+ 6.Kg1 Re8 7.Kh2 Qxf5 8.Ra2
>>>>>Rd8 9.Qxb5 Rxd6 10.Qxc4+ Kg6 11.Ra7 Kh7
>>>>>
>>>>>It seems that the lines are similiar and I suspect that humans did not analyze
>>>>>this line to prove if it is a draw or not a draw.
>>>>>
>>>>>I did not believe that this traingle Qc6-d6-d7-c6 can be a good idea for white
>>>>>but maybe humans are wrong and it is not a draw.
>>>>>
>>>>>It is clear that deeper blue could not find this idea otherwise the programmer
>>>>>could tell the public that it is not a draw so practically kasparov could draw
>>>>>by playing Qe3 but it does not answer the question if Qe3 is objectively a draw.
>>>>>
>>>>>Uri
>>>>
>>>>OK, fine, but obviously Qe3 is the only chance for black and Deep Fritz, Deep
>>>>Shredder and Junior 7 beta see it very quickly. If Deep Blue was so extremely
>>>>fast, why did it expect Qxc6 and didn't see Qe3?
>>>>
>>>>Enrique
>>>
>>>I believe that the answer is simply one of the following or both of them:
>>>
>>>1)Deeper blue is worse than Deep Fritz and could not see the perpetual because
>>>it did not do the right extensions(the main line of Deep Fritz suggests that
>>>Deep Fritz can see the perpetual after many hours so it has a main line that
>>>avoids it)
>>
>>This is totally flawed reasoning.  For a program to see a perpetual in its
>>search, it must meet two conditions.  The conditions are summed up in the
>>following possibilities:
>>
>>1.  It finds a perpetual it can force, regardless of what the opponent does,
>>and it believes that it is losing unless it takes the perpetual.
>>
>>2.  If finds a perpetual the opponent can force, regardless of what it does
>>itself, and it believes that the opponent is losing and will choose to take
>>the perpetual.
>
>I believe that Deep Fritz found that the line Qe3 Qxd6 Re8 h4 is not good
>because black can force a perpetual check after h4
>
>I believe that this is the reason that it changed it's ,mind at depth 22/57 to
>the line Qe3 Qxd6 Re8 Qd7+

No draw in sight after 45...Qe3 46.Qxd6 Re8 47.Qd7+ Re7. I give up.

Comp Deep Blue - Kasparov,G
8/3Qrkp1/R4p1p/1p1PpP2/1Pp1B3/2P1q2P/6P1/5K2 w - - 0 1

Analysis by DEEP FRITZ   :

48.Qxb5 Qxe4 49.d6
  ²  (0.47)   Depth: 3/10   00:00:00
48.Qxb5 Qxe4 49.d6
  ²  (0.47)   Depth: 3/10   00:00:00
48.Qxb5 Qxe4 49.d6 Qxf5+ 50.Kg1 Qb1+
  ²  (0.47)   Depth: 4/13   00:00:00  1kN
48.Qxb5 Qxe4 49.d6 Qxf5+ 50.Kg1 Qb1+
  ²  (0.47)   Depth: 4/13   00:00:00  1kN
48.Qxb5 Qxe4 49.d6 Qxf5+ 50.Kg1 Qb1+
  ²  (0.47)   Depth: 4/13   00:00:00  1kN
48.Qxb5 Qxe4 49.d6 Qxf5+ 50.Kg1 Qb1+
  ²  (0.47)   Depth: 4/13   00:00:00  1kN
48.Qxb5 Qxe4 49.d6 Qxf5+ 50.Kg1 Qb1+
  ²  (0.47)   Depth: 4/13   00:00:00  1kN
48.Qxb5 Qxe4 49.d6 Qxf5+ 50.Kg1 Qb1+
  ²  (0.47)   Depth: 4/13   00:00:00  1kN
48.Qxb5 Qxe4 49.d6 Qxf5+ 50.Kg1 Qb1+ 51.Kh2
  ²  (0.50)   Depth: 5/13   00:00:00  4kN
48.Qxb5 Qxe4 49.d6 Rb7 50.Qc6 Qxf5+ 51.Kg1 Qb1+
  ²  (0.63)   Depth: 6/19   00:00:00  11kN
48.Qxb5 Qxe4 49.d6 Rb7 50.Qc6 Qxf5+ 51.Kg1 Qb1+ 52.Kh2
  ²  (0.66)   Depth: 7/19   00:00:00  27kN
48.Qxb5--
  ²  (0.34)   Depth: 8/21   00:00:00  56kN
48.Qxb5-- Qxe4 49.Qc5 Qd3+ 50.Kg1 Qxc3 51.d6 Qc1+ 52.Kh2 Qf4+ 53.Kh1 Qf1+
  =  (0.19)   Depth: 8/21   00:00:00  104kN
48.Qxb5 Qxe4 49.Qc5 Qd3+ 50.Kg1 Qxc3 51.d6 Qc1+ 52.Kh2 Qf4+ 53.g3 Qd2+
  =  (0.19)   Depth: 9/26   00:00:00  209kN
48.Qc6!
  =  (0.22)   Depth: 9/26   00:00:00  280kN
48.Qc6 Qxe4 49.d6 Qxc6 50.Rxc6 Rd7 51.Ke2 g6 52.Rc7 Ke8 53.Rc8+ Kf7
  =  (0.19)   Depth: 10/25   00:00:00  466kN
48.Qc6 Qxe4 49.d6 Qxc6 50.Rxc6 Rd7 51.Rb6 Ke8 52.Ke2 Rd8 53.Ra6 Kd7
  ²  (0.34)   Depth: 11/29   00:00:01  1382kN
48.Qc6 Qf4+ 49.Bf3 Qc1+ 50.Kf2 Qd2+ 51.Kg1 Qe3+ 52.Kh2 Qf4+ 53.g3 Qxf3
  ²  (0.28)   Depth: 12/31   00:00:02  3627kN
48.Qc6 Qf4+ 49.Bf3 Qc1+ 50.Kf2 Qd2+ 51.Kg1 Qe3+ 52.Kh2 Qf4+ 53.Kh1 Qc1+
  ²  (0.28)   Depth: 13/32   00:00:05  7287kN
48.Qc6 Qxe4 49.d6 Qxf5+ 50.Kg1 Rd7 51.Qxb5 Qe6 52.Qc5 Kg8 53.b5 f5
  =  (0.25)   Depth: 14/34   00:00:13  15907kN
48.Qc6 Qxe4 49.d6 Qxf5+ 50.Kg1 Rd7 51.Qxb5 Qe6 52.Qc5 Kg8 53.b5 f5
  =  (0.19)   Depth: 15/38   00:00:27  32973kN
48.Qc6 Qxe4 49.d6 Qxf5+ 50.Kg1 Rd7 51.Qxb5 Qe6 52.Qc5 Kg8 53.b5 f5
  =  (0.19)   Depth: 16/39   00:01:21  98095kN
48.Qc6 Qxe4 49.d6 Qxf5+ 50.Kg1 Rd7 51.Qxb5 Qe6 52.Qc5 f5 53.Ra7 Kf6
  ²  (0.34)   Depth: 17/45   00:04:11  294777kN
48.Qc6 Qxe4 49.d6 Qxf5+ 50.Kg1 Rd7 51.Qxb5 Qe6 52.Qc5 Kg8 53.b5 Kh7
  ²  (0.44)   Depth: 18/45   00:10:16  723194kN
48.Qc6 Qxe4 49.d6 Qxf5+ 50.Kg1 Rd7 51.Qxb5 Qe6 52.Qc5 Kg6 53.b5 f5
  ²  (0.50)   Depth: 19/48   00:30:51  2157708kN
48.Qc6 Qxe4 49.d6 Qxf5+ 50.Kg1 Rd7 51.Qxb5 Qe6 52.Qc5 Kg6 53.b5 e4
  ²  (0.44)   Depth: 20/50   01:07:13  4718547kN
48.Qc6 Qxe4 49.d6 Qd3+ 50.Kg1 Re8 51.Qd7+ Kf8 52.Kh2 Qd2 53.Ra1 Qf4+
  ²  (0.50)   Depth: 21/52   03:03:15  12898085kN
48.Qc6 Qxe4 49.d6 Qd3+ 50.Kg1 Re8 51.Qd7+ Kf8 52.Kh2 Qd2 53.Ra1 Qf4+
  ²  (0.47)   Depth: 22/53   07:33:37  32277024kN, tb=1
48.Qc6 Qxe4 49.d6 Qd3+ 50.Kg1 Re8 51.Qd7+ Kf8 52.Kh2 Qd2 53.Ra1 Qf4+
  ²  (0.44)   Depth: 23/57   23:09:21  98589124kN, tb=8

(Irazoqui, Cadaqués 02.03.2001)


>I am not sure if the depth 22/57 mean that the longest line is 57 plies and it
>is possible that there is a display bug(assuming that you need 60 plies to see
>the repetition and 57 is not enough).
>
>Another possibility is that hash tables helped Fritz to see it in less plies.
>It is possible that it found a draw in 57 plies in line A and line B that is 61
>plies leaded to one of the positions from line A so it did not need to search
>all the line.
>
>>
>>If a program believes white is losing in this position, then it will think white
>>is trying to repeat and black is not.
>>
>>If a program believes black is losing in this position, then it will think black
>>is trying to repeat and white is not.
>>
>>Those two cases are vastly different.  If DB believed (1) and Fritz believes (2)
>>then comparing their results of looking for a draw is pointless.
>>
>>In any case, the forced (absolutely forced by black with white struggling to
>>avoid the repetition) requires > 60 plies to see.  I don't care _how_ long you
>>give fritz, it is _not_ going to be able to find the forced draw.  It is simply
>>too deep.
>
>Deep Fritz display depth 22/57 plies after 9:15:31 so depth>60 does not seem
>impossible.
>
>Uri



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